The Use of a Novel Immunohistochemical Triple Cocktail in the Subclassification of Resected Non-Small Cell Lung Carcinomas: A Comparative Study With Morphology and Traditional Immunohistochemistry.

Therapy for non-small cell lung carcinoma (NSCLC) is currently determined by histologic subtype and the presence or absence of actionable mutations. Accurate subclassification is therefore essential for appropriate selection of cases for molecular studies and guiding treatment. The gold standard for subclassification of NSCLC is identification of differentiating morphologic features in correlation with diagnostic immunohistochemistry (IHC) in cases of poorly differentiated carcinoma. Whereas Napsin A, TTF1, and p40 antibodies have been used individually for the subtyping of NSCLC, few studies have examined the 3 in cocktail form. Using a novel triple IHC antibody cocktail (TNP) composed of TTF1 (brown nuclear), Napsin A (red granular cytoplasmic), and p40 (red nuclear), a randomized, double-blinded subclassification was performed on a representative histologic section of 32 previously resected primary NSCLCs. TNP results were then compared with the gold-standard diagnosis. TNP accurately identified all (100%, 10/10) squamous cell carcinomas (SCCs) (p40+/TTF1-/Napsin A-) and 89% (16/18) of adenocarcinomas (ADCs) (p40-/TTF1+/Napsin A+). TNP was negative in 7 (20%) tumors (p40-/TTF1-/Napsin A-), including 2 mucinous ADCs. TNP showed no overlapping or discordant immunostaining. Using traditional IHC with p63, CK5/6, and TTF1, all TNP (-) cases remained unclassifiable. With the exception of mucinous ADC, which was TNP negative, all TNP cases correlated with gold-standard diagnosis; 78% of tumors were also definitively classified as either ADC or SCC and required only a single slide for classification.

Comparison of in vivo probe-based confocal laser endomicroscopy with histopathology in lung cancer: A move toward optical biopsy.

BACKGROUND AND OBJECTIVE: The development of novel technologies has increased the yield from transbronchial biopsies while preserving patient safety by guiding biopsies to the area of interest. Other technologies have helped identify pre-cancerous or sessile lesions in the endobronchial space by utilizing interactions between tissue and light at varying wavelengths. Probe-based confocal laser endomicroscopy (pCLE) is a new technology that encompasses the benefits of both guided biopsies and novel optical imaging in one device. This project compares pCLE images to the findings of light microscopy in non-small cell lung cancer (NSCLC). METHODS: Patients who underwent bronchoscopies between July 2012 and January 2013 for evaluation of pulmonary lesions (transbronchial and endobronchial) were recruited. Histopathological images from malignant lesions were compared with the pCLE images obtained from the same area. The microscopic and pCLE images were reviewed side by side with the microscopic findings. RESULTS: Images from pCLE correlate with some histopathological findings. pCLE changes seen in NSCLC consist of mottled elastin, septal studding and disorganization/fragmentation with increased friability. These changes also seem to correlate with degrees of differentiation. CONCLUSIONS: pCLE can identify changes to the elastin composition of the airways and alveoli in lung cancer. These changes correlate with histopathology and may help indicate the presence of malignant changes in vivo.